Re: [Bug-apl] Request to add to the ⎕fio[] a 'function_common_name' as argument

[Xiao-Yong Jin]

I think the point is portability.  Axis notation in function definition 
(especially using an character array as an axis) is not in any standard, afaik, 
so it's impossible to hack such a function in any other APL implementation.  An 
workspace/package uses this FIO function wouldn't be able to function properly 
in other APL implementation.

> On Jan 5, 2017, at 8:16 PM, Christian Robert <address@hidden> wrote:
> 
> I see your point, well, I hacked something, some kind of a wrapper around ⎕FIO
> who give me *very near* of what I wanted, eg: not to have to copy tenth's of 
> functions
> to be able to call the FIO by name.
> 
>      ∇FIO[⎕]∇
>    ∇
> [0]   z←L FIO[X] R;a
> [1]   →(2≠⎕nc 'X')/Noaxis
> [2]   →(0=↑0⍴X)/Number
> [3]   a←  ('errno' 1) ('strerror' 2) ('fopen' 3) ('fclose' 4) ('ferrno' 5) 
> ('fread' 6) ('fwrite' 7) ('fgets' 8) ('fgetc' 9) ('feof' 10)
> [4]   a←a,('ferror' 11) ('ftell' 12) ('fseek_set' 13) ('fseek_cur' 14) 
> ('fseek_end' 15) ('fflush' 16) ('fsync' 17) ('fstat' 18) ('unlink' 19) 
> ('mkdir' 20)
> [5]   a←a,('rmdir' 21) ('printf' 22) ('fwrite' 23) ('popen' 24) ('pclose' 25) 
> ('readfile' 26) ('rename' 27) ('dir' 28) ('ls' 29) ('getcwd' 30)
> [6]   a←a,('access' 31) ('socket' 32) ('bind' 33) ('listen' 34) ('accept' 35) 
> ('connect' 36) ('recv' 37) ('send' 38) ('usend' 39) ('select' 40)
> [7]   a←a,('read' 41) ('write' 42) ('uwrite' 43) ('getsockname' 44) 
> ('getpeername' 45) ('getsockopt' 46) ('setsockopt' 47) ('fscanf' 48)
> [8]   a←a,('open' 3) ('close' 4) ⍝ And some handy aliases
> [9]   →(0=↑⍴X←,⊃((⊂X) ≡¨↑¨a)/a)/Nomatch
> [10]  X←¯1↑X
> [11] Number: →(2≠⎕nc 'L')/Monadic
> [12] Diadic:  z← L ⎕FIO[X] R ⋄ →0
> [13] Monadic: z←   ⎕FIO[X] R ⋄ →0
> [14] Nomatch: ∊("Unknown function:") (X) ⋄ →0
> [15] Noaxis:→(2≠⎕nc 'L')/NoaxisMonadic
> [16] NoaxisDiadic:  z←L ⎕FIO R ⋄ →0
> [17] NoaxisMonadic: z←  ⎕FIO R ⋄ →0
>    ∇
> 
> Only one function is needed to be copied into a workspace (FIO), it 
> understand the axis by number as usual but it also
> understand the axis by name.
> 
> Juergen, feel free to include it into the FILE_IO workspace if you think it 
> may be useful to others (and rename it if you
> want, like FIO∆ or something else).
> 
> not yet 100% tested but you get the idea. I had to use "usend" and "uwrite" 
> for the UTF-8 aware send/write.
> 
> and thanks again for your thoughtful explanation,
> 
> Xtian.
> 
> 
> 
> On 2017-01-04 11:33, Juergen Sauermann wrote:
>> Hi Xtian,
>> 
>> thank you very much for your proposal. I am not too fond of the idea though.
>> Not because of the coding effort on my side, but because of other 
>> considerations.
>> 
>> Consider the following syntactical variants of the same thing, and my 
>> personal
>> judgements of their readability and portability:
>> 
>> *              Syntax                           Readability       
>> Portability**
>> **a.      Z←A ⎕FIO[3] B          worse**         no
>> **b.      Z←A ⎕FIO['fopen'] B    OK            no**
>> **c.      Z←A FIO∆fopen B        better        yes**
>> *
>> then your proposal (which is obviously *b.* above) is IMHO better readable 
>> than a.,
>> but arguably worse than c. (which is *)COPY 5 FILE_IO*). But there are also 
>> some
>> downsides:
>> 
>> - is is an entirely redundant syntax, and
>> - it lacks portability
>> 
>> I believe it is generally a good thing to have a wrapper workspace like 
>> *FILE_IO *because it
>> makes workspaces using it portable to other interpreters (where, of course, 
>> somebody
>> has to implement the functions provided by *FILE_IO*). It was, for example, 
>> possible to change
>> the underlying implementation of *FILE_IO* from a native function to a 
>> system function *⎕FIO*.
>> People using *FILE_IO* at that time would (at least conceptually) not notice 
>> any difference
>> when that change was made, while people not using *FILE_IO* will need to 
>> change their
>> workspaces all over the place when the native variant will finally disappear.
>> 
>> And my experiences with redundant syntax constructs in GNU APL are also 
>> rather negative.
>> Looking backwards I would judge my decision to accept lambdas in GNU APL 
>> (which was, BTW,
>> also proposed by a GNU APL user at that time) as my worst decision in the 
>> GNU APL project so far.
>> 
>> Best Regards,
>> /// Jürgen Sauermann
>> 
>> 
>> On 01/04/2017 07:16 AM, Christian Robert wrote:
>>> I would love to be able to do:
>>> 
>>> fd ←⎕fio['open'] '.bashrc'
>>> ⎕fio['fclose'] fd
>>> 
>>> and so on ...
>>> 
>>> I have a Workspace named "fio" who just do that, but I would love if 
>>> gnu-apl could just understand 'open'/'close'/... rather than just random 
>>> numbers, as actually.
>>> 
>>> Numbers are fine, but a tagged name as in ⎕fio['bind'] would be a *plus*. 
>>> (no need for us to remember the random numbers, only the function name)
>>> 
>>> Yes, a couple of hours for Juergen to code it, but so much 
>>> reliefs/and/easier on our side, as end user.
>>> 
>>> my wishes for 2017 ;-)
>>> 
>>> Xtian.
>>> 
>> 
> 
>      )sic
>      )erase  FIO
>      ∇z←L FIO[X] R;a
> →(2≠⎕nc 'X')/Noaxis
> →(0=↑0⍴X)/Number
> a←  ('errno' 1) ('strerror' 2) ('fopen' 3) ('fclose' 4) ('ferrno' 5) ('fread' 
> 6) ('fwrite' 7) ('fgets' 8) ('fgetc' 9) ('feof' 10)
> a←a,('ferror' 11) ('ftell' 12) ('fseek_set' 13) ('fseek_cur' 14) ('fseek_end' 
> 15) ('fflush' 16) ('fsync' 17) ('fstat' 18) ('unlink' 19) ('mkdir' 20)
> a←a,('rmdir' 21) ('printf' 22) ('fwrite' 23) ('popen' 24) ('pclose' 25) 
> ('readfile' 26) ('rename' 27) ('dir' 28) ('ls' 29) ('getcwd' 30)
> a←a,('access' 31) ('socket' 32) ('bind' 33) ('listen' 34) ('accept' 35) 
> ('connect' 36) ('recv' 37) ('send' 38) ('usend' 39) ('select' 40)
> a←a,('read' 41) ('write' 42) ('uwrite' 43) ('getsockname' 44) ('getpeername' 
> 45) ('getsockopt' 46) ('setsockopt' 47) ('fscanf' 48)
> a←a,('open' 3) ('close' 4) ⍝ Aliases
> →(0=↑⍴X←,⊃((⊂X) ≡¨↑¨a)/a)/Nomatch
> X←¯1↑X
> Number: →(2≠⎕nc 'L')/Monadic
> Diadic:  z← L ⎕FIO[X] R ⋄ →0
> Monadic: z←   ⎕FIO[X] R ⋄ →0
> Nomatch: ∊("Unknown function:") (X) ⋄ →0
> Noaxis:→(2≠⎕nc 'L')/NoaxisMonadic
> NoaxisDiadic:  z←L ⎕FIO R ⋄ →0
> NoaxisMonadic: z←  ⎕FIO R ⋄ →0
> ∇
>